An advantage of digital photography over film is the ability to capture a multitude of images with little or no added expense. As a result, it is common for photographers to accumulate large digital image collections that can be difficult to maintain and difficult to browse serially. Unlike conventional film-based photographs, digital photographs can be loaded onto a computer system. Photographs can then be accessed, organized and manipulated using photograph management software. In managing a collection of digital photographs, it is quite useful to assign labels, or tags, to the photographs, to facilitate subsequent operations involving the photographs. For example, photographs can be labeled with the names of the people that appear in the photographs to facilitate subsequent retrieval of photographs containing a specific person. It is also useful to search a collection of digital photographs that has not been labeled for people that match an identified person.
It can be very time-consuming to label all of the faces that appear in a large collection of digital images, especially when a user must manually locate and label each face in the image. Conventional systems use traditional face recognition techniques to match faces detected in a digital image collection, which may reduce the time required for the labeling process. However, such conventional systems extract a limited set of features from faces that appear in images and use this limited set of features to determine whether the faces match (e.g., belong to the same person). This limited set of features may cause conventional systems to incorrectly match faces. These incorrect matches must be manually corrected by the user, which may be time-consuming for a large digital image collection, and frustrating to the user.
Matching similar faces within a large digital image collection is a computationally expensive effort which takes a significant amount of time and uses a significant amount of resources on a computer system. Conventional systems are not scaled such that the use of time and system resources is limited to desired levels. Rather, the time and system resources used by a conventional system are proportional to the size of a digital image collection. A conventional system processing a large digital image collection may use an unreasonable amount of time and may significantly over-burden the resources of a computer system, which is also frustrating for a user.